Manufacture of soluble nitro dyestuffs and their application



Patented June 9, 1942 UNITED STATES PATENT OFFICE MANUFACTURE OF SOLUBLE NITRO DYE- STUFFS AND THEIR APBLICATION Arthur Howard Knight and Frank Howard Pearman, signors to Blackley, Manchester, England, as- Imperial Chemical Industries Limited, a corporation of Great Britain N Drawing.

Claims.

This invention relates to the manufacture of new water-soluble nitro dyestufis. It also relates to the use of the said new water-soluble nitro dyestufis in coloring acetate artificial silk.

This invention has as an object to provide new dyestufis for coloring acetate artificial silk. A

in which the N 02 group occupies any one of the free positions on the benzene ring, and in which there may be neutral monovalent substituents as defined below, and in which A stands for .-C2H4, C3Hs--, 0r C4Hs, X stands for O- or where R is hydrogen or alkyl (methyl to butyl),

M stands for sodium, potassium, ammonium or other salt forming cation yielding a soluble dyestufi, and the meaning of Y is shown by stating that would stand for phthalic acid, a halogenated phthalic acid, malonic acid or a homologue thereof in which the number of carbon atoms is not more than 6. It will be noted that these dibasic acids are characterized by being per se more or less soluble in water (especially, hot water), and by giving water-soluble alkali-metal salts.

The neutral monovalent substituents above Application July 27, 1939, Serial In Great Britain August 2, 1938 (1) Esterifying a substituted nitrodiphenylamine of the general formula in which A and X stand for the same as before, by treatmentwith substantially an equimolecular proportion of the anhydride of a dicarboxylic acid of general formula Y.(CO2H)2 as above, and then coverting to a soluble salt if necessary.

The esterification is conveniently effected by heating the starting materials together in a suitmentioned are the usual acetate artificial silk dyestufls substituents, for instance chloro, methanesulphonyl, nitro (in addition to the one shown in the general formula) and methoxy substituents, but excluding the solubilising carboxy and sulpho substituents, nuclear or otherwise.

According to the invention we make the new dyestufis by either of the two following processes, namely:

able solvent, e. g., toluene or pyridine. The substituted nitrodiphenylamines may be made, for instance, by interacting appropriate halogenonitrobenzene derivatives containing replaceable halogeno 0r nitro substituents with an appropriate amine of the benzene series.

(2) Reacting a substituted amine of the benzene series of the general formula in which A, X, M and Y stand for the same as before, and in which the phenylene ring may be further substituted as already indicated, with an appropriate nitrohalogenobenzene carrying a replaceable halogen or nitro substituent and also carrying if desired a further substituent or substituents as already indicated, and then converting to soluble salts if necessary.

Also according to the invention tate artificial silk with the dyestufis.

The following examples, in which parts are by weight, illustrate but do not limit the invention.

Example 1 31.9 parts of 2:4-dinitro-4'-,6-hydroxyethoxydiphenylamine are dissolved in 300 parts of dry toluene and to the solution there are added 10 parts of succinic anhydride. The mixture is boiled under a reflux condenser for 5 hours, allowed to cool and filtered. The acid succinic ester of 2:4-dinitro-4'-,B-hydroxyethoxydiphenylamine is obtained in good purity as a red crystalline substance of M. P. 128 C. The pure compound which may be obtained by recrystallisation from ethyl alcohol melts at 132 C.

The ester is suspendedin hot water, and sufficient sodium bicarbonate added to convert it to We color aceits sodium salt,which is then precipitated by parts of ammonia cooling and addition of sodium chloride, filtered and dried. It is obtained as a yellow powder which is soluble in hot water to a yellow solution. It has the probable formula The potassium salt may be obtained in a similar way by using potassium bicarbonate.

Example 2 2 parts of the potassium salt of the acid succinic ester of 2:4 dinitro-l'-,Bhydr0xyeth0xydiphenylamine obtained as in Example 1 are dissolved in 500 parts of warm water and the solution diluted with hot water to give a total of 3000 parts. The temperature is adjusted to 80 C. and parts of sodium chloride are added.

100 parts of acetate artificial silk yarn are treated for minutes at 15 C. in 3000 parts of water containing 3 parts of neutral soap and 3 (e. g. 0.88), well rinsed in water and then put into the above dyebath. After dyeing for 15 minutes at 80-85 C. 10 parts of sodium chloride are added, then after dyeing for another 15 minutes at the same temperature another 10 parts of sodium chloride are added. The yarn is well turned during dyeing and at the end is removed from the dyebath, rinsed and dried. The yarn is colored a clear yellow shade. The dyeing has good fastness properties.

Example 3 To a solution of 30.2 parts of the sodium salt of 4 amino-1-(NN-ethyl-B-hydroxyethylamino) benzene acid succinic ester in 400 parts of Water are added 8.5 parts of sodium bicarbonate and 20.3 parts of 1-chloro-2:4-dinitrobenzene. The mixture is heated at 60-70 C. for 2 hours with stirring. The solium salt of 2::4-dinitro-4'-(NN- ethyl-,B-hydroxyethylamino) diphenylamine acid succinic ester so obtained is precipitated by the addition of sodium chloride. It is purified if necessary by recrystallisation from water and dried at a moderate temperature. It dyes acetate artificial silk in yellowish-brown shades when applied by the method of Example 2. It has the probable formula 4 amino-1-(NN-ethyl-e-hydroxyethylamino) benzene acid succinic ester can be obtained by coupling a diazotised unsulphonated amine of the benzene series (for example aniline or o chloroaniline) with the sodium salt of NN-ethyl-shydroxyethylaniline acid succinic ester in the presence of a slight excess of sodium carbonate, reducing the monoazo compound so obtained in neutral aqueous medium by means of sodium hydrosulphite, rendering the cold reduction mixture jointly alkaline with sodium carbonate and extracting therefrom the regenerated diazotisable amine of the benzene series (e. g. aniline or o-chloroaniline) with ether. The aqueous residue contains the sodium salt of 4-amino-1-(NN- ethyl-5-hydroxyethylamino) benezene acid succinic ester which can be isolated therefrom or alternatively such an aqueous solution can be used directly for the condensation with l-chloro- 2 4-dinitrobenzene.

droxyethylaminodiphenylamine are dissolved in 400 parts of dry toluene and 15.5 parts of phthalic anhydride are added. The mixture is boiled under reflux for 12 hours. The toluene is then removed by steam distillation and the residue extracted with suff cient Warm dilute sodium carbonate to convert the 2:4-dinitro-4'- (NN ethyl B hydroxyethylamino) diphenylamine phthalic acid ester so obtained into its sodium salt. The solution of the sodium salt so obtained is filtered from any tarry matter and the new diphenylamine derivative salted out from the filtrate by the cautious addition of common salt. It is then dried. It dyes actate artificial silk in yellowish-brown shades similar to those given by the dyestuff of Example 3. It has the probable formula r r NaO-C\ /CO-C2H4N-C N NO2 Example 5 ple 2. It has the probable formula Example 6 35.3 parts of 2:4-dinitro-3'-chloro-4'-B-hydroxyethoxydiphenylamine (M. P. 139 0., obtained by condensing 1-chloro-2z4-dinitrobenzene with 2-ch1oro-4-aminophenyl-p-hydroxyethyl ether in ethanol in the presence of anhydrous sodium carbonate) are dissolved in 200 parts of dry toluene and to the solution there are added 105 parts of succinic anhydride. The mixture is boiled under reflux for 2 hours, allowed to cool and filtered. The acid succinic ester of 2 :4-dinitro-2' -ch1oro-4 -c-hydroxyethoxydiphenylamine is obtained in yield and has M. P. 126 C. It is converted to its sodium salt by the method of Example 1, and dyes acetate artificial silk in somewhat greenish-yellow shades of good fastness properties. The sodium salt has the probable formula 31 H N02 NaO- i JCH2CHr--O-OzHr-OO-I N02 Ezrample 7 33.3 parts-of 2:4-dinitro-4-'y-hydroxypropyloxydiphenylamine (M. P. 104 0., obtained by reacting 1-chloro-2z l-dinitrobenzene with p-aminophenyl- -hydroxypropyl ether in ethanol in the presence of sodium carbonate) are reacted with 10 parts of succinic anhydride according to the method of Example 1. The acid succinic ester of 2 :4-dinitro-4' -hydroxypropyloxydiphenylamine is obtained which is converted to its sodium salt by the method of Example 1. It

dyes acetate artificial silk in yellow shades very similar to those given by'the dyestuifs of xam 38.8 parts of 4'-p-hydroxyethoxy-2-nitrodiphenylamine-4-methyl-sulphone (M. P. 152 0., obtained by reacting l-chloro-2-nitrobenzene-4- methyl-sulphone with p-aminophenyl-fi-hydroxyethyl ether in ethanol in the presence of an acid binding agent) are monoesterified by reacting with 10 parts of succinic anhydride according to the method of Example 1. After conversion of the 4'- 3-hydroxyethoxy-2-nitrodiphenylamine- 4-methylsulphone succinic acid ester (orange powder, M. P. 144 C.) to its sodium salt by the method of Example 1, the new dyestufi is obtained as orange crystalline plates which dissolve readily in warm water and dye acetate artificial silk in reddish-yellow shades of very good fastness to light when applied by the method of Example 2. It has the probable formula l i i if Na-O-O-ClEb-OHg-C-OC H4-OOHOOECH3 Example 9 30.8 parts of 5-chloro-2-nitro-4'-fi-hydroxyethoxy-diphenylamine (M. P. 124 0., obtained by reacting l-chloro-S:4-dinitrobenzene with paminophenyl- 8-hydroxyethyl ether in ethanol in the presence of an acid binding agent) are dissolved in 200 parts of dry toluene and to the solution so obtained there are added 10 parts of succinic anhydride. The mixture is boiled under reflux for 5 hours, the toluene is then removed by steam distillation, and the residue extracted with just sufi'icient hot dilute sodium bidroxyethylamino)diphenylamine adipic acid ester, isseparated from a small amount of contaminating tarry material by extraction with boiling ethanol, the alcoholic solution diluted with an equal volume of water and sodium bicarbonate added in sufiicient amount to form the sodium salt of the new adipic acid ester dyestuff. The sodium salt separates on cooling the solution and is filtered oil and dried at a moderate temperature. It is soluble in warm water and dyes acetate artificial silk in yellowish-brown shades when applied by the method of Example 2. It has the probable formula C2H5 N02 i if I l: Nil-O-O-(CHz)l-C-O-CEHrNO -No,

Example 11 To a solution of 27.5 parts of the sodium salt of p-amino-phenol-c-hydroxyethyl ether acid succinic ester in 300 parts of water are added 8.5 parts of sodium bicarbonate and 20.3 parts of 1- chloro-2:4-dinitrobenzene, and the resulting mixture is stirred at 60'70 C. for 2 hours. The 2:4-dinitro 4- ,8 hydroxyethoxydiphenylamine acid succinic ester sodium salt so obtained is then isolated by precipitation with sodium chloride and filtering. It is dried at a moderate temperature. It is identical with the dyestuff of Example 1.

p-Aminophenyl-,8-hydroxyetliyl ether acid succinic ester is obtained by reacting equimolecular proportions of p nitrophenyl-,B-hydroxyethyl ether and succinic anhydride in boiling toluene to give p-nitrophenyl-p-hydroxyethyl ether acid succinic ester which is then reduced to the amine with sodium hydrosulphite in a neutral aqueous medium.

The invention is further illustrated by the examples listed in the following table:

Shade of acid ester Hydroxyalkylated-mtro-d1phenylamme compound *i EE used as starting material Estgnfymg agent is: 335? @21 12 2:4 dinitr0-4-5-hydroxyethoxydiphenylamine Glutaric anhydride Yellow.

13 do 3:4-d1chlorophthalic anhydride" Yellow 14 4 -chloro -2 -nitro -4 -,8 -hydroxyethoxydipheny1amine Succinic anhydride (M. P. of

nitrobenzene with for 16 hours in presence of bo ax) amino) diphenylamine.

(M. P. 78 0., obtainedby reacting 2:5-diohloro-1- p-am1nophenyl-B-hydroxyethyL ether in ethyl alcohol at 130140 C. under pressure Succinic anhydride (M. P. of

Yellowish-brown. resulting acid ester 128 0.).

carbonate to convert the 5-chloro-2-nitro-4'-;3- hydroxyethoxydiphenylamine succinic acid ester to its sodium salt. The solution of the sodium salt so obtained is filtered if necessary and the sodium salt of the new dyestuff is precipitated by addition of common salt. It is filtered off and dried. It dyes acetate artificial silk in reddishyellow shades. It has the probable formula II I I Na-O--CHz-CHz-C-O-CzHrOGL Example 10 wherein D represents the radical of a nitrated diphenylamine, X stands for a non-carbonic link selected from the group consisting of oxygen and imino radicals, Alk designates an alkylene radical having not more than four carbon atoms, while Z represents the radical of a dibasic carboxylic acid whose alkali-metal salt are water-soluble and which is attached to the Alk radical in the form of an ester by means of one of its groups 2. A water-soluble dyestufi for acetate artificial silk, being a compound of the general formula ZAlkOD, wherein D represents the radical of a nitrated diphenyl-amine, Alk designates an alkylene radical having not more than four carbon atoms, while Z represents the radical of a dibasic carboxylic acid whose alkalimetal salts are water-soluble and which is attached to the Alk radical in the form of an ester by means of one of its 0 groups 0 groups 4. A water-soluble dyestuff for acetate artificial silk, being a compound of the general formula wherein R" stands for a member of the. group consisting of hydrogen and lower alkyl radicals and wherein the remaining free positions of the phenylene nuclei are occupied by members of the group consisting of hydrogen and neutral monovalent substituents; X stands for a non-carbonic link selected from the group consisting of oxygen and imino radicals, Alk designates an alkylene radical having not more than four carbon atoms, while Z represents the radical of a dibasic carboxylic acid whose alkali-metal salts are water-soluble and which is attached to the Alk radical in the form of an ester by means of one of its 0 groups 5. A compound of the general formula O-OM wherein D represents the radical of a nitrated diphenylamine, X is an atomic bridge selected from the group consisting of oxygen and imino, Alk designates an alkylene radical having not more than four carbon atoms, Y represents an alkylene radical of not more than 4 carbon atoms,

while M stands. for a water-solubilizing cation.

6. A compound of the general formula Ph oo.oM

wherein D represents the radical of a nitrated diphenylamine, X- is an atomic bridge selected from the group consisting of oxygen and imino, Alk designates an alklene radical having not more than four carbon atoms, Ph represents a phenylene radical, while M stands for a watersolubilizing cation.

8. A dyestuff compound of the general formula Mo-o O-CHzCHrC o-o-mm-o-Orm-Orro:

wherein M stands for a water-solubilizing cation. 9,. A dyestufi compound of the general formula wherein R stands for a member of the group consisting of hydrogen and lower alkyl radical, while M stands for a water-solubilizing cation.

10. A dyestuff compound of the general formula wherein Ph represents a phenylene radical, while M' stands for a water-solub-ilizing cation.

11. A process for producing a water-soluble dyestuff for acetate artificial silk, which comprises subjecting an intermediate of the general wherein Alk is an alkylene radical having not over four carbon atoms while X is a link selected from the group consisting of oxygen and the imino radicals, in optical order, to condensation with a nitrated halogen benzene and to esterification with substantially equimolecular proportion of a anhydride of a dibasic carboxylic acid whose alkali-metal salts are water soluble.

12. A process as in claim 11, the resulting compound being subjected further to neutralization, to convert the remaining free carboxy group of the dibasic acid into a Water-soluble salt thereof.

13. The process of converting a diphenylamine-dyestuff into a water-soluble form suitable for dyeing acetate artificial silk, which comprises esterifying by the aid of the anhydride of a. water-soluble dibasic carboxylic acid a nitrated diphenylamine having in one of the phenyl nuclei a side-chain selected from the group confor a noncarbonic link selected from the group consisting of oxygen and imino radicals, and All: represents an alkylene radical having not more than four carbon atoms.

15. A process as in claim 14, including further the step of converting the remaining carboxy group of the dibasic acid into a water-soluble salt thereof.

ARTHUR HOWARD KNIGHT. FRANK HOWARD PEARMAN.

' CERTIFICATE OF CORRECTlON. Patent No. 2,23 ,516. 7 June 9, 191 2.

ARTHUR EowA D KNIGHT, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 67, for "ben ezene" read "benzenepage 5,'first column,

H H line 5-50, for "1%" read "1"; page 1;, first column, line 28, for

"radical" read --radicals; and second column, line 25 .for "alklene" read --alkylene; line 59, for "radical" read --radicals--; line 65, for a" before anhydride' read -the--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of August, A. D. 19L 2.

A Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

